Metabotropic glutamate receptors are classified pharmacologically into three groups. Of these, group II (mGluR2/mGluR3) bind with adenylcyclase, and inhibit the accumulation of the Forskolin stimulation of cyclic adenosine monophosphate (cAMP) (see Trends Pharmacol. Sci., 14, 13, 1993 (non-patent document 1 mentioned below)). Thus it is suggested that compounds that antagonize the action of group II metabotropic glutamate receptors are effective for the treatment and prevention of acute and chronic psychiatric disorders and neurological diseases. A 2-amino-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid derivative is a compound that has a strong antagonistic effect on group II metabotropic glutamate receptors.